Rock drill apparatus

ABSTRACT

The invention relates to a rock drill apparatus comprising a feed beam ( 1 ) and a rock drill machine moving to-and-fro therealong, a pressure fluid driven feed cylinder ( 4 ) which, by means of a flexible transfer element, is connected so as to transfer the rock drill machine in the longitudinal direction of the cylinder, the feed beam ( 1 ) being provided with a space in its longitudinal direction wherein the feed cylinder ( 4 ) is installed. 
     The rock drill apparatus comprises a measuring device comprising a measuring wheel ( 7   a ) for a measuring line ( 9 ), the measuring wheel ( 7   a ) being connected to rotate a measuring sensor of the measuring device. The measuring line ( 9 ) is routed from the measuring wheel ( 7   a ) to travel into a space of the feed cylinder ( 4 ) in the feed beam and therein in the longitudinal direction of the feed beam ( 1 ), that the measuring line ( 9 ) is by its end connected to a part of the feed cylinder ( 4 ) moving relative to the feed beam ( 1 ) immovably such that when this part moves in a feed direction of the rock drill machine, the measuring line ( 9 ) moves therealong.

BACKGROUND OF THE INVENTION

The invention relates to a rock drill apparatus comprising a feed beam and a rock drill machine moving to-and-fro therealong, a pressure fluid driven feed cylinder which, by means of a flexible transfer element, is connected so as to transfer the rock drill machine in the longitudinal direction of the cylinder, the feed beam being provided with a space in its longitudinal direction wherein the feed cylinder is installed such that its one part, a cylinder tube or a piston rod, is installed relative to the feed beam immovably in the longitudinal direction thereof, while similarly another part, a piston rod or a cylinder tube, moves relative to the feed beam in the longitudinal direction thereof.

BRIEF DESCRIPTION OF THE INVENTION

It is necessary in rock drilling to be able to measure displacement of a rock drill machine in order to find out the length of a drilled hole and, on the other hand, the position of the rock drill machine on a feed beam.

U.S. Pat. No. 6,550,544 discloses a solution wherein a line attached by its ends to both ends of a feed cylinder is routed over a sheave of a measuring device, rotating a sensor therethrough. Depending on the direction of movement of the feed cylinder, the sensor indicates a reading proportional to the displacement of the rock drilling machine, as well as a direction of movement.

A problem with the aforementioned solution is that the structure resides in rather an open space, wherein it is easily subject to damage during use. A further problem is that the measuring member may slip relative to the wheel of the sensor, resulting in measurement error.

An object of the present invention is to provide a measurement apparatus which enables as reliable a measurement result as possible to be achieved and wherein a measuring member is protected better than what is known.

The measurement apparatus according to the invention is characterized in that it comprises a measuring device provided with a measuring wheel, rotatably installed around a transverse axis in relation to the feed beam, for a measuring line, the measuring wheel being connected to rotate a measuring sensor of the measuring device, that the measuring line is routed from the measuring wheel to travel into a space of the feed cylinder in the feed beam and therein in the longitudinal direction of the feed beam, that the measuring line is by its end connected to a part of the feed cylinder moving relative to the feed beam immovably such that when this part moves in a feed direction of the rock drill machine, the measuring line moves therealong, the measuring sensor of the measuring wheel rotating correspondingly, and that it comprises means for rotating the measuring wheel such that the measuring line is allowed to unwind from the measuring wheel when an attachment point of the measuring line in the moving part of the feed cylinder moves away from the measuring device, and, similarly, winds up onto the measuring wheel when the attachment point of the measuring line in the moving part of the feed cylinder moves towards the measuring device.

An idea underlying the invention is that as the measuring member, a measuring device is used wherein the measuring member, such as a measuring line, is arranged around a measuring wheel such that by pulling the measuring member the measuring wheel and a measuring sensor along with it rotate. Further, an essential idea underlying the invention is that a spring is correspondingly connected with the measuring wheel, trying to rotate the measuring wheel in the opposite direction and thus to wind the measuring line onto the measuring wheel. Still another essential idea underlying the invention is that the measuring device is installed outside the feed beam, in the immediate vicinity thereof, and the measuring line is routed via an opening provided in a side of the feed beam so as to travel inside the feed beam preferably between the feed cylinder and the bottom of a groovelike space in the feed beam, whereby it is well protected during use.

BRIEF DESCRIPTION OF THE FIGURES

The invention will be described in closer detail in the accompanying drawings, in which

FIG. 1 is a partly sectioned schematic side view of a feed beam of a rock drill machine.

FIG. 2 is a schematic top view of a part of the feed beam provided with a measuring device, and

FIG. 3 schematically shows a cross-section of the feed beam taken along line A-A in FIG. 2.

DETAILED DESCRIPTION OF SOME EMBODIMENTS OF THE INVENTION

FIG. 1 is a partly sectioned schematic side view of a feed beam of a rock drill machine. It comprises an actual feed beam 1 on which a rock drill machine 2 is movably installed in a longitudinal direction of the feed beam 1. The rock drill machine 2 may be installed movably relative to the feed beam either resting on a separate slide 3 provided between the feed beam and the rock drill machine, or it may be installed directly onto the feed beam 1 movably with respect thereto.

The cross-section of the feed beam 1 is such that its upper part is provided with a U-shaped groove which opens towards the rock drill machine. The feed beam 1 may also be tubular, in which case instead of a groove, the feed beam 1 is provided with a channel-like space inside a tube.

In the groove of the feed beam 1 or in the tubular space of the tubular feed beam thereinside, a feed cylinder 4 is provided which, in a manner known per se, by means of a flexible transfer member, such as a cable or a chain 5, as well as idler wheels 6, is connected so as to transfer the rock drill machine when pressure fluid is fed into either of its pressure fluid spaces. One part of the feed cylinder 4, usually its piston rod 4 a, is at its one end connected relative to the feed beam 1 immovably in its longitudinal direction. Alternatively, a cylinder tube may be attached relative to the feed beam 1 immovably in its longitudinal direction, in which case the piston rod 4 a is movable. In such a feed apparatus, if the idler wheels are connected to move along with the moving part, such as the feed cylinder 4, the rock drill machine 2 moves in a manner known per se at a double speed as compared to the movement of the feed cylinder, so that by measuring the movement of the feed cylinder it is possible to determine the movement, i.e. the displacement, of the rock drill machine and, if desired, also the speed thereof. Such a feed mechanism is known per se to one skilled in the art and commonly completely known, so it is not necessary to explain it in more detail herein.

FIG. 2 is a top view of a part of the feed beam 1 including its measuring device. When a pressure medium is fed in a manner commonly known per se into either of the pressure fluid spaces of the feed cylinder 4, a cylinder tube 4 b moves relative to the feed beam 1 in either direction in its longitudinal direction. FIG. 2 further shows a measuring device 7 attached close to the feed beam 1 onto a side thereof. The measuring device 7 is protected against external impacts e.g. by a protective plate 8.

The measuring device 7 comprises a measuring wheel onto which a measuring member, such as a measuring line, is wound. The measuring wheel is preferably a grooved wheel, so as to prevent the measuring line from slipping off the edges thereof. 7 a A measurement member 9, a measuring line by way of example, is routed from the measuring device 7 such that it passes via an opening formed in the side of the feed beam 1 into the feed beam 1. An idler wheel 10, which is provided with a groove for the measuring line 9, is installed in the opening provided in the feed beam. Thus, the measuring line is allowed to turn smoothly so as to be in parallel with the feed beam 1. An end of the measuring line 9 is connected immovably relative to the feed cylinder 6 e.g. to a separate lug 11 or by another method known per se.

Inside the structure of the measuring device 7 a sensor is provided which, while rotating, generates measuring pulses proportionately to the amount of rotation. The pulses are measured by an electric measuring technique known per se, which makes them easy to communicate to a rock drilling control apparatus, either to be shown or to be used as such as control parameters. When the feed cylinder 4 moves relative to the feed beam 1 in the direction of arrow A in FIG. 2, the feed cylinder pulls the measuring line 9 therealong such that the measuring line unwinds from the measuring wheel 7 a of the measuring device 7 proportionately to the movement of the cylinder tube 4 b. This rotates the measuring wheel 7 a of the measuring device and, therethrough, the sensor known per se which is provided inside the measuring device, thus generating a measuring signal proportionate to the displacement, such as a number of pulses proportionate to a travelling length. When the cylinder tube 4 a of the feed cylinder returns in a direction opposite to that indicated by arrow A, the measuring line 9 is correspondingly allowed to rewind onto the measuring wheel of the measuring device 7. As a member for rewinding the measuring line, the measuring device 7 is e.g. provided with a counter spring, typically a spiral spring, arranged therein in a manner known per se, which, when the line is being drawn out, tightens and tries to resist the line being pulled and which, correspondingly, when the line loosens, rewinds the measuring line 9 into the measuring device 7 and rotates the sensor arranged inside the measuring device in a direction opposite to the pull-out. Thus, the displacement during the return motion may correspondingly be expressed as an electric signal, such as pulses.

FIG. 3 schematically shows a cross-section of the feed beam 1 taken along line B-B in FIG. 2. It shows how the measuring line 9 is routed from the measuring device 7 via the idler wheel 10 into the groove 1 a provided inside the feed beam 1. The measuring line 9 is by its end attached to the lug 11 shown in connection with FIG. 2 and located in the groove 1 a of the feed beam 1, between the feed cylinder 4 and the bottom 1 b of the groove 1 a in the vertical direction thereof. The measuring line 9 is thus well protected against external contact. FIG. 3 further shows how a side of the feed beam 1 is provided with an opening 1 c in which the idler wheel 10 is installed rotationally around a vertical axis.

The invention has been disclosed above in the descriptions and the drawings only by way of example, and it is by no means restricted thereto. The point is that as the measuring device, a solution is used wherein the measuring line is wound around the measuring wheel and it is provided with means, such as a spring or the like, for rotating the measuring wheel such that the measuring line unwinds from the measuring wheel when the attachment point of the measuring line in the cylinder tube moves away from the measuring device and, correspondingly, winds onto the measuring wheel when the attachment point of the measuring line in the cylinder tube moves towards the measuring device. Preferably, a structure equipped with a counter spring is used wherein the counter spring tries to pull the measuring line around the idler wheel of the sensor of the measuring device, simultaneously trying to rotate the sensor, but return means of other kind, such as a pressure fluid driven rotating mechanism or the like, are also possible. Another important point is that the measuring line is routed from the measuring device into the groove provided inside the feed beam, the groove protecting the measuring line against external contact. The measuring line or another flexible measuring member may be routed into the groove through a wall of the feed beam or via a rear end of the feed beam directly into the groove. In the latter case, of course, the measuring device advantageously resides close to the rear end of the feed beam. The position of the measuring device relative to the feed beam may vary, as long as the direction of travel of the measuring member, such as a measuring line, is substantially perpendicular relative to the axis of the measuring wheel and parallel with the tangent of the measuring wheel. The location of the measuring device may also vary according to the application. Consequently, it may be located at a front part of the feed beam, even at the very front part thereof, or, correspondingly, at a rear part, even at the very rear part, thereof. 

1. A rock drill apparatus comprising a feed beam and a rock drill machine moving to-and-fro therealong, a pressure fluid driven feed cylinder which, by means of a flexible transfer element, is connected so as to transfer the rock drill machine in the longitudinal direction of the cylinder, the feed beam being provided with a space in its longitudinal direction wherein the feed cylinder is installed such that its one part, a cylinder tube or a piston rod, is installed relative to the feed beam immovably in the longitudinal direction thereof, while similarly, another part, a piston rod or a cylinder tube, moves relative to the feed beam in the longitudinal direction thereof, wherein the rock drill comprises a measuring device provided with a measuring wheel, rotatably installed around a transverse axis in relation to the feed beam, for a measuring line, the measuring wheel being connected to rotate a measuring sensor of the measuring device, that the measuring line is routed from the measuring wheel to travel into a space of the feed cylinder in the feed beam and therein in the longitudinal direction of the feed beam, that the measuring line is by its end connected to a part of the feed cylinder moving relative to the feed beam immovably such that when this part moves in a feed direction of the rock drill machine, the measuring line moves therealong, the measuring sensor of the measuring wheel rotating correspondingly, and means for rotating the measuring wheel such that the measuring line is allowed to unwind from the measuring wheel when an attachment point of the measuring line in the moving part of the feed cylinder moves away from the measuring device, and, similarly, winds up onto the measuring wheel when the attachment point of the measuring line in the moving part of the feed cylinder moves towards the measuring device, whereby a wall of the feed beam is provided with an opening via which the measuring line is routed into the space of the feed beam, and that the opening is provided with an idler wheel along whose surface the measuring line turns so as to be parallel with the feed beam.
 2. A rock drill apparatus as claimed in claim 1, wherein the measuring device is installed in a rear part of the feed beam.
 3. A rock drill apparatus as claimed in claim 1, wherein the measuring device is installed in a front part of the feed beam.
 4. A rock drill apparatus as claimed in claim 1 wherein space in the feed beam in which the feed cylinder is installed is a groove provided therein and facing towards the rock drill machine.
 5. A rock drill apparatus as claimed in claim 1, wherein the means for rotating the measuring wheel comprise, in the measuring device, a counter spring which, when the measuring line is being pulled and the measuring wheel is rotating, tightens and, correspondingly, during movement of the feed cylinder in an opposite direction when the measuring line loosens, rotates the measuring wheel, keeping the measuring line tight.
 6. A rock drill apparatus as claimed in claim 4, wherein the means for rotating the measuring wheel comprise, in the measuring device, a counter spring which, when the measuring line is being pulled and the measuring wheel is rotating, tightens and, correspondingly, during movement of the feed cylinder in an opposite direction when the measuring line loosens, rotates the measuring wheel, keeping the measuring line tight. 